Remove VALUE=DATE-TIME from DTSTART, DTEND, DTSTAMP

CHANGES.rst

@@ -11,6 +11,9 @@ Minor changes:
   Ref: #473
   Fixes: #472
   [jacadzaca]
+- Make datetime value shorter by removing the value parameter where possible.
+  Fixes: #318
+  [jacadzaca], [niccokunzmann]
 
 Breaking changes:
 

docs/usage.rst

@@ -239,7 +239,7 @@ identifier (if applicable) are automatically added here::
 
     >>> lines = event.to_ical().splitlines()
     >>> assert (
-    ...     b"DTSTART;TZID=Europe/Vienna;VALUE=DATE-TIME:20101010T100000"
+    ...     b"DTSTART;TZID=Europe/Vienna:20101010T100000"
     ...     in lines)
 
 
@@ -314,7 +314,7 @@ Write to disk::
   >>> directory = tempfile.mkdtemp()
   >>> f = open(os.path.join(directory, 'example.ics'), 'wb')
   >>> f.write(cal.to_ical())
-  570
+  522
   >>> f.close()
 
 

src/icalendar/prop.py

@@ -289,20 +289,18 @@ def __init__(self, dt):
             raise ValueError('You must use datetime, date, timedelta, '
                              'time or tuple (for periods)')
         if isinstance(dt, datetime):
-            self.params = Parameters({'value': 'DATE-TIME'})
+            self.params = Parameters()
         elif isinstance(dt, date):
             self.params = Parameters({'value': 'DATE'})
         elif isinstance(dt, time):
             self.params = Parameters({'value': 'TIME'})
         elif isinstance(dt, tuple):
             self.params = Parameters({'value': 'PERIOD'})
 
-        if (isinstance(dt, datetime) or isinstance(dt, time))\
-                and getattr(dt, 'tzinfo', False):
-            tzinfo = dt.tzinfo
-            tzid = tzid_from_dt(dt)
-            if tzid != 'UTC':
-                self.params.update({'TZID': tzid})
+        tzid = tzid_from_dt(dt) if isinstance(dt, (datetime, time)) else None
+        if not tzid is None and tzid != 'UTC':
+            self.params.update({'TZID': tzid})
+
         self.dt = dt
 
     def to_ical(self):

src/icalendar/tests/calendars/created_calendar_with_unicode_fields.ics

@@ -6,16 +6,16 @@ X-WR-CALNAME:äöü ÄÖÜ €
 X-WR-RELCALID:12345
 BEGIN:VEVENT
 SUMMARY:Non-ASCII Test: ÄÖÜ äöü €
-DTSTART;VALUE=DATE-TIME:20101010T100000Z
-DTEND;VALUE=DATE-TIME:20101010T120000Z
+DTSTART:20101010T100000Z
+DTEND:20101010T120000Z
 UID:123456
-CREATED;VALUE=DATE-TIME:20101010T000000Z
+CREATED:20101010T000000Z
 DESCRIPTION:icalendar should be able to de/serialize non-ascii.
 LOCATION:Tribstrül
 END:VEVENT
 BEGIN:VEVENT
 SUMMARY:åäö
-DTSTART;VALUE=DATE-TIME:20101010T000000Z
+DTSTART:20101010T000000Z
 END:VEVENT
 BEGIN:VEVENT
 DESCRIPTION:äöüßÄÖÜ

src/icalendar/tests/test_issue_318_skip_default_parameters.py

@@ -0,0 +1,27 @@
+"""Some parameters are specified as default by the RFC 5545.
+
+These tests make sure that these parameter values are not added to the
+properties.
+
+Example:
+
+       DTSTART;VALUE=DATE-TIME:20190616T050000Z
+equals DTSTART:20190616T050000Z
+"""
+import pytest
+from icalendar import Event
+from datetime import datetime
+
+
+@pytest.mark.parametrize("attr", [
+    "DTSTART",
+    "DTEND",
+    "DTSTAMP",
+])
+def test_datetime_in_event(attr):
+    """Check that the "VALUE=DATE-TIME" is absent because not needed."""
+    event = Event()
+    event.add(attr, datetime(2022, 10, 13, 9, 16, 42))
+    ics = event.to_ical()
+    assert b"VALUE=DATE-TIME" not in ics
+

src/icalendar/tests/test_parsing.py

@@ -124,8 +124,8 @@ def test_timezones_to_ical_is_inverse_of_from_ical(timezones):
     assert timezone.to_ical() == timezone.raw_ics
 
 @pytest.mark.parametrize('date, expected_output', [
-    (datetime(2012, 7, 16, 0, 0, 0), b'DTSTART;VALUE=DATE-TIME:20120716T000000Z'),
-    (datetime(2021, 11, 17, 15, 9, 15), b'DTSTART;VALUE=DATE-TIME:20211117T150915Z')
+    (datetime(2012, 7, 16, 0, 0, 0), b'DTSTART:20120716T000000Z'),
+    (datetime(2021, 11, 17, 15, 9, 15), b'DTSTART:20211117T150915Z')
 ])
 def test_no_tzid_when_utc(utc, date, expected_output):
     '''Issue #58  - TZID on UTC DATE-TIMEs

src/icalendar/tests/test_timezoned.py

@@ -149,21 +149,21 @@ def test_create_to_ical_pytz(self):
         test_out = test_out.decode('utf-8')
 
         vtimezone_lines = "BEGIN:VTIMEZONE|TZID:Europe/Vienna|X-LIC-LOCATION:"
-        "Europe/Vienna|BEGIN:STANDARD|DTSTART;VALUE=DATE-TIME:19701025T03"
+        "Europe/Vienna|BEGIN:STANDARD|DTSTART:19701025T03"
         "0000|RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10|RRULE:FREQ=YEARLY;B"
         "YDAY=-1SU;BYMONTH=3|TZNAME:CET|TZOFFSETFROM:+0200|TZOFFSETTO:+01"
-        "00|END:STANDARD|BEGIN:DAYLIGHT|DTSTART;VALUE=DATE-TIME:19700329T"
+        "00|END:STANDARD|BEGIN:DAYLIGHT|DTSTART:19700329T"
         "020000|TZNAME:CEST|TZOFFSETFROM:+0100|TZOFFSETTO:+0200|END:DAYLI"
         "GHT|END:VTIMEZONE"
         self.assertTrue(vtimezone_lines in test_out)
 
-        test_str = "DTSTART;TZID=Europe/Vienna;VALUE=DATE-TIME:20120213T100000"
+        test_str = "DTSTART;TZID=Europe/Vienna:20120213T100000"
         self.assertTrue(test_str in test_out)
         self.assertTrue("ATTENDEE:sepp" in test_out)
 
         # ical standard expects DTSTAMP and CREATED in UTC
-        self.assertTrue("DTSTAMP;VALUE=DATE-TIME:20101010T081010Z" in test_out)
-        self.assertTrue("CREATED;VALUE=DATE-TIME:20101010T081010Z" in test_out)
+        self.assertTrue("DTSTAMP:20101010T081010Z" in test_out)
+        self.assertTrue("CREATED:20101010T081010Z" in test_out)
 
     def test_create_to_ical_zoneinfo(self):
         cal = icalendar.Calendar()
@@ -232,21 +232,21 @@ def test_create_to_ical_zoneinfo(self):
         test_out = test_out.decode('utf-8')
 
         vtimezone_lines = "BEGIN:VTIMEZONE|TZID:Europe/Vienna|X-LIC-LOCATION:"
-        "Europe/Vienna|BEGIN:STANDARD|DTSTART;VALUE=DATE-TIME:19701025T03"
+        "Europe/Vienna|BEGIN:STANDARD|DTSTART:19701025T03"
         "0000|RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10|RRULE:FREQ=YEARLY;B"
         "YDAY=-1SU;BYMONTH=3|TZNAME:CET|TZOFFSETFROM:+0200|TZOFFSETTO:+01"
-        "00|END:STANDARD|BEGIN:DAYLIGHT|DTSTART;VALUE=DATE-TIME:19700329T"
+        "00|END:STANDARD|BEGIN:DAYLIGHT|DTSTART:19700329T"
         "020000|TZNAME:CEST|TZOFFSETFROM:+0100|TZOFFSETTO:+0200|END:DAYLI"
         "GHT|END:VTIMEZONE"
         self.assertTrue(vtimezone_lines in test_out)
 
-        test_str = "DTSTART;TZID=Europe/Vienna;VALUE=DATE-TIME:20120213T100000"
+        test_str = "DTSTART;TZID=Europe/Vienna:20120213T100000"
         self.assertTrue(test_str in test_out)
         self.assertTrue("ATTENDEE:sepp" in test_out)
 
         # ical standard expects DTSTAMP and CREATED in UTC
-        self.assertTrue("DTSTAMP;VALUE=DATE-TIME:20101010T081010Z" in test_out)
-        self.assertTrue("CREATED;VALUE=DATE-TIME:20101010T081010Z" in test_out)
+        self.assertTrue("DTSTAMP:20101010T081010Z" in test_out)
+        self.assertTrue("CREATED:20101010T081010Z" in test_out)
 
 
     def test_tzinfo_dateutil(self):

src/icalendar/tests/test_unit_cal.py

@@ -227,12 +227,12 @@ def test_cal_Component_add(self):
 
         lines = comp.to_ical().splitlines()
         self.assertTrue(
-            b"DTSTART;TZID=Europe/Vienna;VALUE=DATE-TIME:20101010T100000"
+            b"DTSTART;TZID=Europe/Vienna:20101010T100000"
             in lines)
-        self.assertTrue(b"CREATED;VALUE=DATE-TIME:20101010T120000Z" in lines)
-        self.assertTrue(b"DTSTAMP;VALUE=DATE-TIME:20101010T120000Z" in lines)
+        self.assertTrue(b"CREATED:20101010T120000Z" in lines)
+        self.assertTrue(b"DTSTAMP:20101010T120000Z" in lines)
         self.assertTrue(
-            b"LAST-MODIFIED;VALUE=DATE-TIME:20101010T160000Z" in lines
+            b"LAST-MODIFIED:20101010T160000Z" in lines
         )
 
     def test_cal_Component_add_no_reencode(self):
@@ -388,7 +388,7 @@ def test_cal_Calendar(self):
         self.assertEqual(
             cal.subcomponents[0].to_ical(),
             b'BEGIN:VEVENT\r\nSUMMARY:Python meeting about calendaring\r\n'
-            + b'DTSTART;VALUE=DATE-TIME:20050404T080000\r\nUID:42\r\n'
+            + b'DTSTART:20050404T080000\r\nUID:42\r\n'
             + b'END:VEVENT\r\n')
 
         # Write to disc